The Small Wind Certification Council (SWCC) has recently certified two wind turbines suitable for residential-scale systems: the Evance R9000 and Kestrel e400nb.
Kestrel Renewable Energy’s (kestrelwind.co.za) e400nb is a three-blade, upwind, horizontal-axis wind turbine with a 13.1-foot diameter and a swept area of 12.6 square meters. It is rated at 3 kW, and has options for battery charging (48 V) or being grid-tied via a Power-One Aurora PVI-3.6 inverter.
The machine has fiberglass blades, yaws passively, and has a mechanical brake for manual shutdown. Governing is via pitch control.
The estimated annual energy at an 11 mph average wind speed is 3,900 kWh. At an 8.9 mph average, estimated energy is 1,900 kWh per year. The warranty is two years.